SEAD

SEAD (Suppression of Air Defenses), also known as "Wild Weasel," is a mission role pertaining to disabling Surface to Air Missiles (SAMs), AAA emplacements, Early Warning, and Command and Control systems. This can be accomplished by destruction of weapon systems, destruction of radar emitters, or at minimum forcing radar emitters to shut down to evade the threat of radiation seeking missiles.

The Tools

AGM-88C HARM - The quintessential American SEAD missile, this missile is equipped with a radiation seeking head allowing it to home in on radar emitters. Launch aircraft can designate emitters visible via RWR for it to chase, or they launch it in self-protect mode, which will cause it to fly in circles above the launch point searching for emitters on its own. It's range is highly dependent on altitude and speed of the launch platform, but is typically within 30-50nm.
AGM-122 SideARM - In the early 90's, the US Navy recycled a bunch of aging AIM-9Cs by replacing the seeker with an anti-radiation seeker. Being effectively a hacked sidewinder, its range is well within the engagement envelope of most of the air defense threats in the game. While it's quite conceivable to fly low and fast to use terrain masking to close to range, the reality is that most of the emitters you could engage safely could just as safely be taken out by Mavericks, JDAMs, JSOWs, and high altitude bomb drops. Also, while the missile was capable of shooting a radar off of an armored vehicle in real life, such detailed damage modeling is not present in DCS ground vehicles, which are only disabled once hp=0. In other words, you need to kill the vehicle to disable it, and this missile just does not have the punch. Useless.
LD-10 - Continuing the trend of hacking Air-to-Air missiles, this is a variant of the Chinese SD-10. Able to strike out to 20-40nm, it remains sufficient for taking out short to medium range SAMs. However, you cannot directly select which emitter to lock on to, which makes it better for self-defense applications. That said, even the mighty SA-10 can't see these coming.
Kh-58U - The Russian equivalent to the AGM-88C HARM, with comparable range.
Kh-25MPU - Smaller range than the Kh-58, but also faster and harder to shoot down.
Ground Attack Weapons - Not every air defense system has a radar, and those that do are quite capable of turning off their radar to prevent an anti-radiation-missile from targeting them. Traditional bombs, missiles, and general-purpose ground attack weapons are still capable of engaging air-defenses, but many lack range and all lack the ability to acquire the target as quickly as a proper anti-radiation missile.

Before You Fly

Did I pack Anti-Radiation Missiles? - these are critical for accomplishing the mission.
Did I turn on my RWR? - This is absolutely critical for finding radar SAMs, and also for knowing when you are being shot at.
Is my ECM installed/running? - This degrades the range that SAMs can engage you at, making your chances of keeping your takeoff to landing ratio closer to 1:1 just a little better.
Did I pack and program Chaff/Flares? - You will be flying inside a SAM engagement envelope. This also means you will be shot at. Chaff and flares will be critical to your survival. Chaff bursts of around 4-8 per second should throw off most SAMs.
Am I packing too heavy? - One of the tradeoffs you will need to make based on intelligence is how much ordinance you will carry. Since you are going to be shot at by SAMs, you need to pack as light as you can so you can maneuver to evade them. Avoid stupidly heavy bombs and fuel tanks unless absolutely necessary.

During the Flight

The Mission Commander will task your flight with sites to suppress. To do so, you purposefully fly into the threat area of the threat hoping that they target you. Once your RWR picks up the threat you want to attack, you fire an anti-radiation missile at it. The missile will either track to and destroy the target, or the target will shut down their radar to prevent your missile from tracking. Either way, you win, because the enemy is not using their radar to track your friends. Repeat as necessary.

Shit to Watch Out For

Since one of the big components of this role is flying within the threat envelope of a SAM, you must be especially prepared to evade missile fire from SAM sites. Be familiar with what SAM systems you are expected to encounter, so that you can best evade them.

Depending on how evil the mission designer chose to be, missile launchers could be located up to 20-30 miles away from the tracking radars that drive them, which could result in missiles approaching from many directions, including underneath you.

Long range missile systems, such as SA-3s, SA-10s, and Patriots are very expensive, and typically of great strategic importance. As such, their components are frequently covered by a variety of cheaper short range options, including IR threats and AAA to cover against low-flying aircraft attempting to sneak up upon them. Any low approach should be accomplished with great speed, and with a steady trail of flares behind you.

Certain systems are capable of shooting down ARMs. You may wish to salvo a few depending on the target and the units covering it.

A Comprehensive List of ADS in DCS

Semi-Active Radar Homers / Remote Commanded

System	RWR Code
Hawk	HK
SA-2	2
SA-3	3
SA-6	6
SA-8	8
SA-11	11, SD
SA-15	15

Upon lock, you should fire your ARM (or let a buddy fire theirs) and either put the emitter on your 3 or 9, or simply fly out of the threat radius. Should a launch occur, dive 10 degrees, pop chaff and locate the smoke trail quickly (remember, it may not be in the direction of the emitter!). Depending on whether or not the chaff fooled the SAM and where the smoke plume is, you may need to change tactics and focus on wasting the missiles energy by turning your 3 or 9 to it, performing a split s, and running away.

Older systems, such as the SA-2, are incapable of locking low targets and can have their missiles dragged into the ground.

The SA-11 is particularly annoying in that each launcher has its own tracking radar, and will happily spike you from well out of range. As such, it can take quite a few HARMS to bring it down completely. However, killing the Search Radar will degrade it severely, as the launchers will be unable to locate anything outside of visual range without it.

Active Radar Homers

System	RWR Code
Patriot	P, PA
SA-10	10, BB

Both of these systems are absolutely terrifying, especially if the mission designer chose to hide launchers far from the tracking radars. Because the missiles themselves have emitters, it is no longer sufficient to defeat the tracking radar. Thus, it is even more critical to locate the smoke trail, and be prepared to evade the missile itself. Fortunately, since the missile has an emitter, the RWR will tell you where it is at the terminal phase. Unfortunately, they call it the terminal phase for a reason, so you must act quickly.